import Foundation
import XCTest
#if os(macOS)
import AppKit
#endif
@testable import DocsKit

final class DocumentRenderReconciliationTests: XCTestCase {
    @MainActor func testAcknowledgedOptimisticTextUpdatesMappingWithoutReplacingCharacters() {
        #if os(macOS)
        let storage = NSTextStorage(string: "Hello 😀\n", attributes: [.docsNode: "old", .docsOffset: 0, .font: NSFont.systemFont(ofSize: 12)])
        let observer = StorageObserver()
        storage.delegate = observer
        let next = NSAttributedString(string: storage.string, attributes: [.docsNode: "published", .docsOffset: 7, .font: NSFont.systemFont(ofSize: 12)])
        DocumentRenderReconciliation.apply(next, to: storage)
        XCTAssertEqual(storage.string, next.string)
        XCTAssertEqual(storage.attribute(.docsNode, at: 0, effectiveRange: nil) as? String, "published")
        XCTAssertEqual(storage.attribute(.docsOffset, at: 0, effectiveRange: nil) as? Int, 7)
        XCTAssertFalse(observer.editedCharacters)
        XCTAssertTrue(observer.editedAttributes)
        #endif
    }
    @MainActor func testRemoteReplacementPreservesUnicodeAndAllAttributes() {
        let storage = NSMutableAttributedString(string: "A😀old Z", attributes: [.docsNode: "old"])
        let next = NSMutableAttributedString(string: "A😁日本語 Z", attributes: [.docsNode: "new"])
        next.addAttribute(.docsOffset, value: 12, range: NSRange(location: 3, length: 3))
        DocumentRenderReconciliation.apply(next, to: storage)
        XCTAssertTrue(storage.isEqual(to: next))
    }
    #if os(macOS)
    @MainActor func testMacLogicalPaperWidthDoesNotReflowAtNarrowZoomedViewport() {
        let narrow = DocsPageGeometry(viewportWidth: 350, paged: true)
        let wide = DocsPageGeometry(viewportWidth: 1200, paged: true)
        XCTAssertEqual(narrow.textWidth, 468)
        XCTAssertEqual(wide.textWidth, narrow.textWidth)
        XCTAssertEqual(narrow.paperWidth, 612)
    }
    #endif
}
#if os(macOS)
@MainActor private final class StorageObserver: NSObject, @preconcurrency NSTextStorageDelegate {
    var editedCharacters = false
    var editedAttributes = false
    func textStorage(_ textStorage: NSTextStorage, didProcessEditing editedMask: NSTextStorageEditActions, range editedRange: NSRange, changeInLength delta: Int) {
        editedCharacters = editedCharacters || editedMask.contains(.editedCharacters)
        editedAttributes = editedAttributes || editedMask.contains(.editedAttributes)
    }
}
#endif